This project is an attempt to develop specific probes for hallucinogen receptors. Of interest is the stereochemistry of the receptor and the equivalence of the aromatic substituents of phenethylamines and tryptamines. Several enantiomeric compounds are proposed for synthesis and resolution with absolute configuration to be determined by X-ray crystallography. Also proposed is the development of an asymmetric synthesis for enantiomers of alpha-methyltryptamines.